Study of the vascular pattern in oral lichen planus

Oral Lichen Planus is a relatively frequent disease. Its etiopathogenesis is still unknown and it can undergo malignant transformation during its evolution. Thus, data which could contribute to the knowledge of the biology of this disease are particularly significant. The present study involves a quantitative evaluation of the vascular pattern of oral lichen planus. A portion of biopsy specimens taken for histopathologic diagnosis was processed to mark vascular walls using the histoenzymic technique for ATPase activity demonstration. Stained Sections were then evaluated in a semi-automatic magnetic image analyser. The stereologic parameters studied, showed there is no vascular increase in lichen with regard to normal mucosae or leukoplakias, since the number of vascular walls did not show significant differences. Instead, a significant increase was observed in the vascular area. The association of these parameters, indicates that lichen is a more congestive lesion than the other two conditions studied. These findings indicate that the modifications of the vascular pattern could play a role in the etiopathogenesis of oral lichen planus and suggest that the observation of these changes could be a useful element in the histopathologic diagnosis.

Angina bullosa hemorrhagica

BACKGROUND

In 1967, Badham used the term angina bullosa hemorrhagica (ABH) to describe an entity we already knew as traumatic oral hemophlyctenosis (TOH) (1933) and later renamed recurrent oral hemophlyctenosis (ROH) (1971).

OBJECTIVES

The objective of this study was to review and discuss the literature, and to report 54 new cases seen between 1989 and 1996.

MATERIALS AND METHODS

Fifty-four patients were thoroughly assessed to determine the clinical features, histology, etiology, pathogenesis, differential diagnosis, and therapy.

RESULTS

In 35 patients (64.8%), the lesions predominated on the palate and in nine (16.6%) on the oral mucosa. The incidence was similar in both sexes (women, 52%; men, 48%) and the condition affected mostly the 51-70-year age group. ABH was never documented in children under 10 years of age. In 24 cases (44.4%), diabetes mellitus, hyperglycemia, and/or a family history of diabetes was found.

CONCLUSIONS

ABH is a disorder more common than the literature would suggest. Although the causes may be multiple (mucosal trauma, inhaled corticosteroids), the available data indicate that, in these patients, the presence of an alteration in glucose metabolism should be considered.

p53, Rb, and cyclin D1 expression in human oral verrucous carcinomas

BACKGROUND

The verrucous carcinoma (VC), a tumor with low grade malignancy, appears to be associated with tobacco and human papillomavirus. The pathobiology of these tumors has not been extensively studied, and molecular genetic alterations have not been reported. In this study we investigated by immunohistochemistry the expression of p53, Rb, and cyclin D1 in a series of well-defined oral VC. Changes in the expression of these genes have been commonly reported in a variety of human tumors.

METHODS

We studied 29 cases of VC, fixed in formalin and embedded in paraffin. Immunohistochemistry was carried out using the avidin-biotin immunoperoxidase technique. Polyclonal antibody CM-1 was used for p53, a rabbit polyclonal human RB antibody, Rb-WL-1 antibody for Rb and a rabbit polyclonal human cyclin D antibody for cyclin D1.

RESULTS

Positive p53 expression (protein accumulation) was detected in 15 of the 29 VC analyzed. In some cases, p53-positive areas were small foci but in most of the cases extensive positive areas were observed. None of the cases studied showed alterations of Rb protein. The expression of cyclin D1 was determined in 18 cases of VC. Positive nuclear immunostaining was seen in 11 cases.

CONCLUSIONS

p53 protein accumulation is frequently observed in these tumors suggesting possible mutations of this gene in VC. Overexpression of cyclin D1 but no alterations of Rb staining were also observed in this low grade tumor suggesting that Rb may be functionally inactivated by overexpression of cyclin D1 or HPV infection.

Inhibition of benzoyl peroxide-induced tumor promotion and progression by copper(II)(3,5-diisopropylsalicylate)2

The ability of a biomimetic superoxide dismutase agent, copper(II)(3,5-diisopropylsalicylate)2 (CuDIPS), to modulate benzoyl peroxide (BzPo)-induced tumor promotion and progression in mouse skin multistage carcinogenesis was evaluated. The results showed a significant inhibition of tumor incidence by CuDIPS pretreatment during promotion-progression. Different types of tumors were developed: papillomas, keratoacanthomas and squamous cell carcinomas. There was a significant increase in the keratoacanthoma-papilloma ratio when the period of treatment with BzPo was prolonged, which was inhibited by CuDIPS pretreatment. CuDIPS induced a significant inhibition of malignant conversion. Our results suggest that reactive oxygen species could be important in BzPo-induced promotion and progression.

Morphometric study of nucleolar organizer regions in human oral normal mucosa, papilloma and squamous cell carcinoma

A morphometric study of nucleolar organizer regions (NOR) was performed to analyze their distribution, volume, number and shape in the different strata of human normal oral mucosa epithelium and papilloma and in squamous cell carcinoma employing microphotographs of silver-stained paraffin sections. The different NOR-related parameters evidenced significant differences between normal mucosa, papilloma and squamous cell carcinoma. The functional polarity of normal mucosa epithelium and of papilloma is also evidenced in terms of NOR-related parameters. The discriminative value of certain NOR parameters was demonstrated.